Field of the Invention
Exemplary embodiments of the present invention relate to a radar apparatus, and more particularly, to a radar apparatus capable of supporting all of a short range function and middle and LRR functions, which is configured to support all the short and middle and LRR functions through a single apparatus or system configuration and to have most of the elements of the radar apparatus implemented on a single chip, thereby being capable of achieving miniaturization, high density integration and lower power.
Description of the Related Art
Recently, research continues to be carried out on a short range and high resolution radar in millimeter and sub-millimeter bands according to an increase in the demand for the short range and high resolution radar. A high-resolution radar system capable of determining or resolving the distance between adjacent objects is used for industrial and military purposes in various ways. A vehicle radar system is chiefly used in real life. The vehicle radar system is an essential technology for implementing an intelligent transportation system may be called a safe driving system for a vehicle that has been developed in order to prevent an accident that may occur due to poor weather conditions or a driver's carelessness by detecting a motion of another vehicle or object that moves or stops within a radius of about 250 m or less.
A conventional high-resolution radar system detects objects in various directions by scanning the objects using a precise mechanical device in order to obtain high space resolution within a small field of view. In such a radar system, a multi-beam antenna capable of electrical scanning and a digital beamforming technology are instead used because a corresponding mechanical device is increased if the number of antennas is increased in order to increase space resolution. For this reason, the conventional high-resolution radar system is chiefly applied to a small radar for a vehicle.
A vehicle radar technology may be classified into a Long Range Radar (LLR) capable of detecting an object within about 250 m or less and a Short Range Radar (SRR) capable of detecting an object within 60 m or less. A frequency of a 77 GHz band is chiefly used in the LRR, and a frequency of a 24 GHz band is chiefly used in the SRR.
For example, an existing vehicle radar configured to perform both an Adaptive Cruise Control (ACC) function and a Stop & Go function and applied to an application for front collision warning and prevention (e.g., an Automatic Emergency Brake (AEB)) has a configuration in which radar sensors for a short range and a radar sensor for middle/long ranges are separated and installed, as illustrated in FIG. 1. In such a combined ACC and AEB system, the middle and LRR for ACC performs a collision warning and prevention function by detecting a traffic line ahead of a section of 0˜200 m along which a vehicle being driven travels, and the SRRs for an AEB perform a collision warning and prevention function by detecting vehicles that break into traffic lines ahead of a section of 0˜60 m along which the vehicle being driven travels.
There is recently proposed an integrated radar for a short range and middle/long ranges, wherein the radar sensors for a short range and the radar sensor for middle/long ranges separated as described above are integrated as illustrated in FIG. 2.
In the conventional vehicle radar apparatus, however, LRR mode characterized by a relatively long detection range and a narrow field of view and SRR mode characterized by a short detection range and a wide field of view depending on their uses are limitedly applied to a single apparatus or system.